Hugo is in the youth ranks at Benfica, who Joao Felix won the 2018-19 Primeira Liga with before leaving for Atletico in a €126million move last July.
The 20-year-old Portugal international believes his younger sibling has what it takes to break into the first team and forge a successful career in football.
"If he listens to those who want to help him, he is going to be successful," Joao Felix told BTV.
"He does things I couldn't do at his age. He has everything to do well and reach the first team. For his age he works a lot.
"We both like to score. He takes better free-kicks than me, I am better at penalties, but we both play more or less in the same positions.
"In football you have to play simple, but we like to do something different, something that excites the crowd, and we have some similarities.
"Since we were little we saw each other playing and tried to do the same things."
Joao Felix also got his hands on some silverware at international level with Portugal at the Nations League Finals last year.
With Atleti having booked their place in the quarter-finals of the Champions League with a dramatic extra-time victory over Liverpool in their last match before the coronavirus pandemic led to the suspension of most major sport across the globe, he is hoping for more.
"You need a bit of luck to win the Champions League," said Joao Felix.
"But we hope to [win] it and if I won the Champions League, it would be something very good in my life and my career.
"[It would be] one of the happiest days [of my life] - the dream I've always had since I've been playing football."